omfs

2.  Radiotherapy destroys neoplastic (and normal) cells by
interfering with nuclear material necessary [or
reproduction
 The faster the cellular turnover, the more susceptible the
tissue.
 Normal tissues with rapid turnover rates are also
affected.
 Hematopoietic cells, epithelial cells, and endothelial
cells are affected soon after radiotherapy begins.

3.  SHORT TERM EFFECTS
› 1 to 2 weeks ---- erythrema progressing to mucositis with or
without ulceration
› Pain and dysphagia
› Destruction of taste buds
 LONG TERM EFFECTS
› Breakdown and delayed healing
› Sub mucosal fibrosis

5.  Antibiotic lozenges containing
› amphotericin,
› tobramycin, and
› neomycin.
› When symptoms are severe, viscous lidocaine can be useful.

6.  Irradiated muscle becomes fibrotic and tends to
contract resulting in TRISMUS.
 Insidious in onset, usually occurring over the first year
after radiation therapy and is painless.
 PROBLEMS
› Feeding. Additionally
› Difficult to perform dental work and to provide a general
anesthetic.

7.  Salivary gland epithelium has a slow turnover rate but
because of the destruction of the fine vasculature there
is
› Atrophy
› fibrosis, and
› degeneration
 CLINICAL
› Xerostomia (the decreased production of
 A dry mouth may be the patient's most significant
complaint.

8.  Difficulty with Tasting, Chewing and swallowing
 Esophageal dysfunction
 Nutritional compromises
 Higher frequency of intolerance to medications
 Glossitis, candidiasis, angular cheilitis, halitosis, and bacterial
sialadenitis;
 Decreased resistance to loss of tooth structure from attrition,
abrasion, and erosion
 Loss of buffering capacity
 Increased susceptibility to mucosal injury
 Inability to wear dental prostheses; and rampant caries.

9.  Rampant caries; cervical caries
 Increased periodontitis

11. Sipping water throughout the day.
Salivary substitutes contains
• Several of the ions in saliva and other ingredients (e.g.,glycerin) to mimic the lubricating action of saliva.
Advised not to use products containing alcohol or strong flavors, which may irritate the
mucosa.
Avoid sugar-containing products
Artificial saliva

12. Efforts to stimulate the patient's residual saliva.
Sugar-free chewing gum stimulates saliva production as long as there is
some saliva being produced
Drugs
•Pilocarpine hydrochloride 5 mg 4 times
•Cevimeline hydrochloride 30 mg 3 times
Parasympathomimetic agents that function primarily as muscarinic
agonists, causing stimulation of exocrine gland secretion.

13.  Devitalization of the bone by cancericidal doses of
radiation.
 Elimination of fine vasculature leading to non vitality of
bone due to endarteritis
 Sharp areas on the alveolar ridge will not smooth
themselves.
 Mandible commonly affected with nonhealing,
ulcerations and osteoradionecrosis.

14.  Depends on
› Location
› Dose of RT
› Insult in form of extraction

15.  Marx 3 H theory
› Hypoxia
› Hypovascularity
› Hypocellularity
 New Theory

17.  Overgrowth of anaerobic species and fungi.
› Candida albicans commonly thrives in the oral cavities of
patients who have been irradiated.
 Application of topical antifungal agents, such as
nystatin.
 Another oral rinse frequently prescribed is 0 . 1%
chlorhexidine (Peridex).
 This agent has been shown to have potent in vitro
antibacterial and antifungal effects.

18.  CONDITION OF RESIDUAL DENTITION
› Extract All teeth with poor prognosis.
 DEPENDS UPON
1. PATIENT'S DENTAL AWARENESS

19. 2. IMMEDIACY OF RADIOTHERAPY
› If the radiotherapist feels that therapy must be instituted urgently, there
may not be time to perform the necessary extractions and allow for initial
healing of the extraction sites.
› Dentist may maintain the dentition but must work closely with the patient
in an attempt to maintain oral health as optimally as possible.
3. RADIATION LOCATION
› The more salivary glands and bone involved in the field of radiation, the
more severe the resultant xerostomia.
› If radiation to the major salivary glands and a portion of the mandible,
preirradiation extractions should be considered.
› Radiotherapist may agree to delay radiation for 1 to 2 weeks if the dentist
feels that time is necessary to allow the extraction sites to begin to heal.

20. 4. RADIATION DOSE
› The higher the radiation dose, the more severe the normal
tissue damage.
› Amount of radiation should be discussed.
› SCC requires a large dose of radiation (greater than 6000 rad
[ 60 Gy] )to effect a result.
› When the total dose falls below 5000 rad (50 Gy) , long-term
side effects, such as xerostomia and osteoradionecrosis, are
dramatically decreased.

21. Every tooth to be maintained must be restored to the best state of health
obtainable.
Thorough prophylaxis and topical fluoride
Oral hygiene measures and instructions
Any sharp cusps should be rounded
Impressions for dental casts should be obtained for fabrication of custom fluoride
trays.
Stoppage of tobacco and alcohol

23. PRE RADIATION
EXTRACTIONS

24.  If the wound fails to heal, the radiotherapy will be
delayed.
 If the radiation is delivered before the wound heals,
healing will take months or even years.

25. Atraumatic exodontia apply.
Remove a good portion of the alveolar process along with the teeth and achieve
a primary soft tissue closure.
The teeth are usually removed in a surgical manner, with flap reflection and
generous bone removal.
Atraumatic handling of flaps.
Burs or files should be used to smooth the bony edges under copious irrigation.
Prophylactic antibiotics are indicated.

27.  When the soft tissues have healed sufficiently,
radiotherapy may begin.
 Traditionally, 7 to 14 days gap
 However, radiotherapy should be delayed for 3 weeks
after extraction, if possible.

28.  Further delay RT
 Daily local wound care with irrigations
 Postoperatively administered antibiotics are mandatory
until the soft tissues have healed.

29.  If the patient has a partially erupted mandibular third
molar, remove to prevent pericoronal infection.
 If full bony impaction, do not remove

31. Rinsing of the mouth at least 10 times a day with saline or chlorhexidine rinses.
Review of patient each week for observation and oral hygiene evaluations.
If an overgrowth of C. albicans occurs, nystatin or clotrimazole should be applied
Physiotherapy exercises.
All patients must be weighed weekly to determine whether they are maintaining an
adequate nutritional status.
Nutrition; NG or PEG

33. Visit every 3 to 4 months.
A prophylaxis with topical fluoride.
The patient should be fitted with custom trays to deliver topical
fluoride applications.
1% fluoride rinse for 5 minutes each day has been found to decrease
the incidence of radiation caries
All patients should also be monitored for the possible onset of trismus.

34. Composites and
amalgam are the
materials of choice.
Full crowns not
warranted.
Oral hygiene
measures, including
fluoride application,
must be reinforced.

35. If pulpitis
Endodontic intervention with systemic
antibiotics can be carefully
performed and the tooth can be
ground out of occlusion and
maintained.
Root canal treatment is difficult
because of a progressive sclerosis of
the pulp chamber.
In such instances, the tooth can
simply be amputated above the
gingiva and left in place.

36.  The most tricky and undesirable extraction
 Defer if possible or restore
 If emergency
› Atraumatic extraction
› Adequate soft tissue closure
› Systemic antibiotics
› Hyperbaric oxygen therapy

37. Administration of oxygen under pressure to the patient.
HBO has been shown to increase the local tissue oxygenation and vascular ingrowth into
the hypoxic tissues.
PROTOCOL
•20 and 30 HBO dives before extraction
•10 more dives immediately after extractions.
The patient usually undergoes one HBO session each day.
4 to 6 weeks to get the 20 to 30 treatments before surgery, and 2 weeks of treatment after
surgery.

39. Patients who were edentulous before radiotherapy manage nicely.
Patients rendered edentulous just before or after radiotherapy exhibit mucosal ulcerations and
subsequent osteoradionecrosis.
Soft denture liners can be used.
Ordinary dentures best.
When dentures are constructed the denture base and occlusal table are designed so that forces
are distributed evenly throughout the alveolar ridge and that lateral forces on the denture are
eliminated.

40. Challenges.
• No normal anatomy
• No vestibules to accommodate a denture flange.
• Hard and soft tissue defects and deficits.
• Bone may have poor form for support of a tissue-borne prosthesis.
• Such patients have nonpliable soft tissue flaps
The use of implant-borne prostheses are preferred from a
functional standpoint.

41.  The more radiation delivered, the higher the failure rate for
endosseous implants. 45 GY
 The longer the duration between radiation treatment and
implantation, the higher the failure rate. No loading for 6 months
 When implants in irradiated patients fail, they usually fail early,
before prosthetic reconstruction, indicating a failure of
osseointegration
 The combination of radiation and chemotherapy has a
particularly negative effect
 Implant survival in irradiated patients higher in the maxilla
 Shorter implants have the worst prognosis
 HBO treatment reduces implant failure rates

42.  Discontinue wearing any prosthesis
 Maintain a good state of oral health.
 Irrigations should be instituted to remove necrotic
debris.
 Only occasionally are systemic antibiotics necessary
 Any loose sequestra are removed,
 No attempt is made initially to close the soft tissues over
the exposed bone.

43.  For nonhealing wounds or extensive areas of
osteoradionecrosis
› Resection of the exposed bone and a margin of unexposed
bone and primary soft tissue closure can be attempted.
› HBO therapy in conjunction with surgical intervention
› Reconstructive efforts with bone grafts.
› Free microvascular grafting techniques more popular